Thanks for all the replies, I had a few laughs from them. CM is right, as is joispoi with his technical description. The fifth wheel set up is purely for convenience, as they already had the tandem dolly and it would keep the front of the machine reasonably level.
Don't feel bad, Grader4me, at least you had a go and CPS, if stumps get in the way, yes that too.
Those of you that have followed my posts know, there is a lot of limestone in our area and this limestone is the mainstay of our crushing and contracting business. For those of you who don't know, this link explains the history behind our operation.
https://www.heavyequipmentforums.com/Forum/showthread.php?t=7186&page=4
Thousands of acres of farm land here has limestone outcrops or sheet limestone, which obviously reduces the productivity of the land and is also hard on machinery. Over the years, different methods have been used to clear this land and make it more productive. It started with ploughs, then hand picking the stones, to mechanical pickers to pick and stockpile the stone, which is the raw material for our business and then on to large ribbed rollers which smash the stone up and break the points of the limestone ridges. In the last few years, a contractor has been crushing or milling the worst areas in the paddocks for farmers, using the FAE three point linkage type crushers mounted on Fendt Tractors. The problem with these machines, is that they are just not built heavy enough for continual work in this situation and it is also very costly for the farmer, so consequently, with grain prices not so good, he hasn't been getting much work.
A farmer friend of mine, who has a lot of stony country, decided to do something about it. He bought an old milling machine/road profiler that was retired, but still had a good engine and drum on it. He took the tracks off it and mounted the fith wheel king pin, so that he could pull it with the tandem dolly. He fabricated the rear axle on pivots, so that the machine can be raised and lowered with the hydraulic rams. It weighs about 16 tonnes and a GM 8V92 provides the power. He is cutting about 6-7 feet at a depth of 4 to 6 inches and travels 300 metres an hour. The John Deere tractor has the IVT transmission, which can go as slow as 50 metres an hour. He would like to go a bit deeper and a bit faster, but he is having a bit of trouble with the drum belts slipping when he does. The machine crushes the limestone with no effort at all. You may think that this is a slow and costly operation, which it is, but it is also a once only operation and will never have to be done again. This chap has done fifty acres so far and he feels that he is improving the value of his land by anything up to $1,000 per acre. I have already seen the improvement in his crops on the stoney country.
My interest in this is that there is a huge amount of country with limestone on it and I think there is a contracting opportunity there, if the cost can be brought down to an acceptable level for the farmers, so who knows, one day I might be looking for some retired milling machines. The other upside of this is, if we can design some way of lifting the 100-150mm of crushed material, screen off the coarse rock and return the finer rock and soil, say -30mm, to the paddock, we would have an unlimited supply of partially crushed rock for our business.
Here are some more pics of the machine. The first one is the FAE crusher which is fine for what it is designed for, but not strong enough for this sort of work.
RnR.